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vlc/modules/access/alsa.c
Rémi Denis-Courmont 8943c7cad7 alsa: fix double precision codec mapping
2019-01-24 18:31:32 +02:00

527 lines
16 KiB
C
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/*****************************************************************************
* alsa.c: ALSA capture module for VLC
*****************************************************************************
* Copyright (C) 2012 Rémi Denis-Courmont
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
*****************************************************************************/
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <assert.h>
#include <sys/types.h>
#include <poll.h>
#include <alsa/asoundlib.h>
#include <vlc_common.h>
#include <vlc_demux.h>
#include <vlc_aout.h>
#include <vlc_plugin.h>
#define HELP_TEXT N_( \
"Pass alsa:// to open the default ALSA capture device, " \
"or alsa://SOURCE to open a specific device named SOURCE.")
#define STEREO_TEXT N_("Stereo")
#define RATE_TEXT N_("Sample rate")
static int Open (vlc_object_t *);
static void Close (vlc_object_t *);
static const int rate_values[] = { 192000, 176400,
96000, 88200, 48000, 44100,
32000, 22050, 24000, 16000,
11025, 8000, 4000
};
static const char *const rate_names[] = { N_("192000 Hz"), N_("176400 Hz"),
N_("96000 Hz"), N_("88200 Hz"), N_("48000 Hz"), N_("44100 Hz"),
N_("32000 Hz"), N_("22050 Hz"), N_("24000 Hz"), N_("16000 Hz"),
N_("11025 Hz"), N_("8000 Hz"), N_("4000 Hz")
};
vlc_module_begin ()
set_shortname (N_("ALSA"))
set_description (N_("ALSA audio capture"))
set_capability ("access", 0)
set_category (CAT_INPUT)
set_subcategory (SUBCAT_INPUT_ACCESS)
set_help (HELP_TEXT)
add_obsolete_string ("alsa-format") /* since 2.1.0 */
add_bool ("alsa-stereo", true, STEREO_TEXT, STEREO_TEXT, true)
add_integer ("alsa-samplerate", 48000, RATE_TEXT, RATE_TEXT, true)
change_integer_list (rate_values, rate_names)
add_shortcut ("alsa")
set_callbacks (Open, Close)
vlc_module_end ()
/** Helper for ALSA -> VLC debugging output */
/** XXX: duplicated from ALSA output */
static void Dump (vlc_object_t *obj, const char *msg,
int (*cb)(void *, snd_output_t *), void *p)
{
snd_output_t *output;
char *str;
if (unlikely(snd_output_buffer_open (&output)))
return;
int val = cb (p, output);
if (val)
{
msg_Warn (obj, "cannot get info: %s", snd_strerror (val));
return;
}
size_t len = snd_output_buffer_string (output, &str);
if (len > 0 && str[len - 1])
len--; /* strip trailing newline */
msg_Dbg (obj, "%s%.*s", msg, (int)len, str);
snd_output_close (output);
}
#define Dump(o, m, cb, p) \
Dump(VLC_OBJECT(o), m, (int (*)(void *, snd_output_t *))(cb), p)
static void DumpDevice (vlc_object_t *obj, snd_pcm_t *pcm)
{
snd_pcm_info_t *info;
Dump (obj, " ", snd_pcm_dump, pcm);
snd_pcm_info_alloca (&info);
if (snd_pcm_info (pcm, info) == 0)
{
msg_Dbg (obj, " device name : %s", snd_pcm_info_get_name (info));
msg_Dbg (obj, " device ID : %s", snd_pcm_info_get_id (info));
msg_Dbg (obj, " subdevice name: %s",
snd_pcm_info_get_subdevice_name (info));
}
}
static void DumpDeviceStatus (vlc_object_t *obj, snd_pcm_t *pcm)
{
snd_pcm_status_t *status;
snd_pcm_status_alloca (&status);
snd_pcm_status (pcm, status);
Dump (obj, "current status:\n", snd_pcm_status_dump, status);
}
#define DumpDeviceStatus(o, p) DumpDeviceStatus(VLC_OBJECT(o), p)
typedef struct
{
snd_pcm_t *pcm;
es_out_id_t *es;
vlc_thread_t thread;
vlc_tick_t start;
vlc_tick_t caching;
snd_pcm_uframes_t period_size;
unsigned rate;
} demux_sys_t;
static void Poll (snd_pcm_t *pcm, int canc)
{
int n = snd_pcm_poll_descriptors_count (pcm);
struct pollfd ufd[n];
unsigned short revents;
snd_pcm_poll_descriptors (pcm, ufd, n);
do
{
vlc_restorecancel (canc);
while (poll (ufd, n, -1) == -1);
canc = vlc_savecancel ();
snd_pcm_poll_descriptors_revents (pcm, ufd, n, &revents);
}
while (!revents);
}
static void *Thread (void *data)
{
demux_t *demux = data;
demux_sys_t *sys = demux->p_sys;
snd_pcm_t *pcm = sys->pcm;
size_t bytes;
int canc, val;
canc = vlc_savecancel ();
bytes = snd_pcm_frames_to_bytes (pcm, sys->period_size);
val = snd_pcm_start (pcm);
if (val)
{
msg_Err (demux, "cannot prepare device: %s", snd_strerror (val));
return NULL;
}
for (;;)
{
block_t *block = block_Alloc (bytes);
if (unlikely(block == NULL))
break;
/* Wait for data */
Poll (pcm, canc);
/* Read data */
snd_pcm_sframes_t frames, delay;
vlc_tick_t pts;
frames = snd_pcm_readi (pcm, block->p_buffer, sys->period_size);
pts = vlc_tick_now ();
if (frames < 0)
{
block_Release (block);
if (frames == -EAGAIN)
continue;
val = snd_pcm_recover (pcm, frames, 1);
if (val == 0)
{
msg_Warn (demux, "cannot read samples: %s",
snd_strerror (frames));
snd_pcm_state_t state = snd_pcm_state (pcm);
switch (state)
{
case SND_PCM_STATE_PREPARED:
val = snd_pcm_start (pcm);
if (val < 0)
{
msg_Err (demux, "cannot prepare device: %s",
snd_strerror (val));
return NULL;
}
continue;
case SND_PCM_STATE_RUNNING:
continue;
default:
break;
}
}
msg_Err (demux, "cannot recover record stream: %s",
snd_strerror (val));
DumpDeviceStatus (demux, pcm);
break;
}
/* Compute time stamp */
if (snd_pcm_delay (pcm, &delay))
delay = 0;
delay += frames;
pts -= vlc_tick_from_samples(delay, sys->rate);
block->i_buffer = snd_pcm_frames_to_bytes (pcm, frames);
block->i_nb_samples = frames;
block->i_pts = pts;
block->i_length = vlc_tick_from_samples(frames, sys->rate);
es_out_SetPCR(demux->out, block->i_pts);
es_out_Send (demux->out, sys->es, block);
}
return NULL;
}
static int Control (demux_t *demux, int query, va_list ap)
{
demux_sys_t *sys = demux->p_sys;
switch (query)
{
case DEMUX_GET_TIME:
*va_arg (ap, vlc_tick_t *) = vlc_tick_now () - sys->start;
break;
case DEMUX_GET_PTS_DELAY:
*va_arg (ap, vlc_tick_t *) = sys->caching;
break;
//case DEMUX_SET_NEXT_DEMUX_TIME: still needed?
case DEMUX_HAS_UNSUPPORTED_META:
case DEMUX_CAN_RECORD:
case DEMUX_CAN_PAUSE:
case DEMUX_CAN_CONTROL_PACE:
case DEMUX_CAN_CONTROL_RATE:
case DEMUX_CAN_SEEK:
*va_arg (ap, bool *) = false;
break;;
default:
return VLC_EGENERIC;
}
return VLC_SUCCESS;
}
static const vlc_fourcc_t formats[] = {
[SND_PCM_FORMAT_S8] = VLC_CODEC_S8,
[SND_PCM_FORMAT_U8] = VLC_CODEC_U8,
[SND_PCM_FORMAT_S16_LE] = VLC_CODEC_S16L,
[SND_PCM_FORMAT_S16_BE] = VLC_CODEC_S16B,
[SND_PCM_FORMAT_U16_LE] = VLC_CODEC_U16L,
[SND_PCM_FORMAT_U16_BE] = VLC_CODEC_U16B,
[SND_PCM_FORMAT_S24_LE] = VLC_CODEC_S24L32,
[SND_PCM_FORMAT_S24_BE] = VLC_CODEC_S24B32,
[SND_PCM_FORMAT_U24_LE] = VLC_CODEC_U32L, // TODO: replay gain
[SND_PCM_FORMAT_U24_BE] = VLC_CODEC_U32B, // ^
[SND_PCM_FORMAT_S32_LE] = VLC_CODEC_S32L,
[SND_PCM_FORMAT_S32_BE] = VLC_CODEC_S32B,
[SND_PCM_FORMAT_U32_LE] = VLC_CODEC_U32L,
[SND_PCM_FORMAT_U32_BE] = VLC_CODEC_U32B,
[SND_PCM_FORMAT_FLOAT_LE] = VLC_CODEC_F32L,
[SND_PCM_FORMAT_FLOAT_BE] = VLC_CODEC_F32B,
[SND_PCM_FORMAT_FLOAT64_LE] = VLC_CODEC_F64L,
[SND_PCM_FORMAT_FLOAT64_BE] = VLC_CODEC_F64B,
//[SND_PCM_FORMAT_IEC958_SUBFRAME_LE] = VLC_CODEC_SPDIFL,
//[SND_PCM_FORMAT_IEC958_SUBFRAME_BE] = VLC_CODEC_SPDIFB,
[SND_PCM_FORMAT_MU_LAW] = VLC_CODEC_MULAW,
[SND_PCM_FORMAT_A_LAW] = VLC_CODEC_ALAW,
//[SND_PCM_FORMAT_IMA_ADPCM] = VLC_CODEC_ADPCM_?, // XXX: which one?
[SND_PCM_FORMAT_MPEG] = VLC_CODEC_MPGA,
[SND_PCM_FORMAT_GSM] = VLC_CODEC_GSM,
//[SND_PCM_FORMAT_SPECIAL] = VLC_CODEC_?
[SND_PCM_FORMAT_S24_3LE] = VLC_CODEC_S24L,
[SND_PCM_FORMAT_S24_3BE] = VLC_CODEC_S24B,
[SND_PCM_FORMAT_U24_3LE] = VLC_CODEC_U24L,
[SND_PCM_FORMAT_U24_3BE] = VLC_CODEC_U24B,
[SND_PCM_FORMAT_S20_3LE] = VLC_CODEC_S24L, // TODO: replay gain
[SND_PCM_FORMAT_S20_3BE] = VLC_CODEC_S24B, // ^
[SND_PCM_FORMAT_U20_3LE] = VLC_CODEC_U24L, // ^
[SND_PCM_FORMAT_U20_3BE] = VLC_CODEC_U24B, // ^
[SND_PCM_FORMAT_S18_3LE] = VLC_CODEC_S24L, // ^
[SND_PCM_FORMAT_S18_3BE] = VLC_CODEC_S24B, // ^
[SND_PCM_FORMAT_U18_3LE] = VLC_CODEC_U24L, // ^
[SND_PCM_FORMAT_U18_3BE] = VLC_CODEC_U24B, // ^
};
#ifdef WORDS_BIGENDIAN
# define C(f) f##BE, f##LE
#else
# define C(f) f##LE, f##BE
#endif
/* Formats in order of decreasing preference */
static const uint8_t choices[] = {
C(SND_PCM_FORMAT_FLOAT_),
C(SND_PCM_FORMAT_S32_),
C(SND_PCM_FORMAT_U32_),
C(SND_PCM_FORMAT_S16_),
C(SND_PCM_FORMAT_U16_),
C(SND_PCM_FORMAT_FLOAT64_),
C(SND_PCM_FORMAT_S24_3),
C(SND_PCM_FORMAT_U24_3),
SND_PCM_FORMAT_MPEG,
SND_PCM_FORMAT_GSM,
SND_PCM_FORMAT_MU_LAW,
SND_PCM_FORMAT_A_LAW,
SND_PCM_FORMAT_S8,
SND_PCM_FORMAT_U8,
};
static uint16_t channel_maps[] = {
AOUT_CHAN_CENTER, AOUT_CHANS_2_0, AOUT_CHANS_3_0 /* ? */,
AOUT_CHANS_4_0, AOUT_CHANS_5_0 /* ? */, AOUT_CHANS_5_1,
/* TODO: support 7-8 channels - need channels reodering */
};
static int Open (vlc_object_t *obj)
{
demux_t *demux = (demux_t *)obj;
if (demux->out == NULL)
return VLC_EGENERIC;
demux_sys_t *sys = vlc_obj_malloc(obj, sizeof (*sys));
if (unlikely(sys == NULL))
return VLC_ENOMEM;
/* Open the device */
const char *device = demux->psz_location;
if (device == NULL || !device[0])
device = "default";
const int mode = SND_PCM_NONBLOCK
/*| SND_PCM_NO_AUTO_RESAMPLE*/
| SND_PCM_NO_AUTO_CHANNELS
/*| SND_PCM_NO_AUTO_FORMAT*/;
snd_pcm_t *pcm;
int val = snd_pcm_open (&pcm, device, SND_PCM_STREAM_CAPTURE, mode);
if (val != 0)
{
msg_Err (demux, "cannot open ALSA device \"%s\": %s", device,
snd_strerror (val));
return VLC_EGENERIC;
}
sys->pcm = pcm;
msg_Dbg (demux, "using ALSA device: %s", device);
DumpDevice (VLC_OBJECT(demux), pcm);
/* Negotiate capture parameters */
snd_pcm_hw_params_t *hw;
es_format_t fmt;
unsigned param;
int dir;
snd_pcm_hw_params_alloca (&hw);
snd_pcm_hw_params_any (pcm, hw);
Dump (demux, "initial hardware setup:\n", snd_pcm_hw_params_dump, hw);
val = snd_pcm_hw_params_set_rate_resample (pcm, hw, 0);
if (val)
{
msg_Err (demux, "cannot disable resampling: %s", snd_strerror (val));
goto error;
}
val = snd_pcm_hw_params_set_access (pcm, hw,
SND_PCM_ACCESS_RW_INTERLEAVED);
if (val)
{
msg_Err (demux, "cannot set access mode: %s", snd_strerror (val));
goto error;
}
snd_pcm_format_t format = SND_PCM_FORMAT_UNKNOWN;
for (size_t i = 0; i < sizeof (choices) / sizeof (choices[0]); i++)
if (snd_pcm_hw_params_test_format (pcm, hw, choices[i]) == 0)
{
val = snd_pcm_hw_params_set_format (pcm, hw, choices[i]);
if (val)
{
msg_Err (demux, "cannot set sample format: %s",
snd_strerror (val));
goto error;
}
format = choices[i];
break;
}
if (format == SND_PCM_FORMAT_UNKNOWN)
{
msg_Err (demux, "no supported sample format");
goto error;
}
assert ((size_t)format < (sizeof (formats) / sizeof (formats[0])));
es_format_Init (&fmt, AUDIO_ES, formats[format]);
fmt.audio.i_format = fmt.i_codec;
param = 1 + var_InheritBool (demux, "alsa-stereo");
val = snd_pcm_hw_params_set_channels_max (pcm, hw, &param);
if (val)
{
msg_Err (demux, "cannot restrict channels count: %s",
snd_strerror (val));
goto error;
}
val = snd_pcm_hw_params_set_channels_last (pcm, hw, &param);
if (val)
{
msg_Err (demux, "cannot set channels count: %s", snd_strerror (val));
goto error;
}
assert (param > 0);
assert (param < (sizeof (channel_maps) / sizeof (channel_maps[0])));
fmt.audio.i_channels = param;
fmt.audio.i_physical_channels = channel_maps[param - 1];
param = var_InheritInteger (demux, "alsa-samplerate");
val = snd_pcm_hw_params_set_rate_max (pcm, hw, &param, NULL);
if (val)
{
msg_Err (demux, "cannot restrict rate to %u Hz or less: %s", 192000,
snd_strerror (val));
goto error;
}
val = snd_pcm_hw_params_set_rate_last (pcm, hw, &param, &dir);
if (val)
{
msg_Err (demux, "cannot set sample rate: %s", snd_strerror (val));
goto error;
}
if (dir)
msg_Warn (demux, "sample rate is not integral");
fmt.audio.i_rate = param;
sys->rate = param;
sys->start = vlc_tick_now ();
sys->caching = VLC_TICK_FROM_MS(var_InheritInteger (demux, "live-caching"));
param = sys->caching;
val = snd_pcm_hw_params_set_buffer_time_near (pcm, hw, &param, NULL);
if (val)
{
msg_Err (demux, "cannot set buffer duration: %s", snd_strerror (val));
goto error;
}
param /= 4;
val = snd_pcm_hw_params_set_period_time_near (pcm, hw, &param, NULL);
if (val)
{
msg_Err (demux, "cannot set period: %s", snd_strerror (val));
goto error;
}
val = snd_pcm_hw_params_get_period_size (hw, &sys->period_size, &dir);
if (val)
{
msg_Err (demux, "cannot get period size: %s", snd_strerror (val));
goto error;
}
if (dir > 0)
sys->period_size++;
/* Commit hardware parameters */
val = snd_pcm_hw_params (pcm, hw);
if (val)
{
msg_Err (demux, "cannot commit hardware parameters: %s",
snd_strerror (val));
goto error;
}
Dump (demux, "final HW setup:\n", snd_pcm_hw_params_dump, hw);
/* Kick recording */
aout_FormatPrepare (&fmt.audio);
sys->es = es_out_Add (demux->out, &fmt);
demux->p_sys = sys;
if (vlc_clone (&sys->thread, Thread, demux, VLC_THREAD_PRIORITY_INPUT))
{
es_out_Del (demux->out, sys->es);
goto error;
}
demux->pf_demux = NULL;
demux->pf_control = Control;
return VLC_SUCCESS;
error:
snd_pcm_close (pcm);
return VLC_EGENERIC;
}
static void Close (vlc_object_t *obj)
{
demux_t *demux = (demux_t *)obj;
demux_sys_t *sys = demux->p_sys;
vlc_cancel (sys->thread);
vlc_join (sys->thread, NULL);
snd_pcm_close (sys->pcm);
}
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